Malodorous emissions from open organic slurry storage structures are a nuisance for nearby receptors. Large scale livestock facilities and subsequent malodorous gas emissions therefrom have become a source of national controversy.
Many methods have been tried to control malodorous emissions on open organic slurry storage basins: impervious covers with and without gas collection systems, bioaugmentation, chemical additives, enzymes and full and partial aerobic treatment systems. Impervious cover systems are quite costly and gas collection systems require significant initial capital investment as well as ongoing maintenance expense. Bioaugmentation, chemical additives and enzymes have not delivered consistent odor control and usually require significant ongoing labor and maintenance costs in addition to product costs. Aerobic methods work most convincingly, but excessive cost has prevented widespread acceptance of aeration as the preferred method of odor control. Floating biomats of straw provide partial aeration, have performed well and are reasonably economical. But it is difficult to place and maintain a solid straw cover on areas greater than two hundred feet wide. They also require regular maintenance to cover an increasing slurry storage surface area as sloped earthen basins fill, and to fill holes that appear as straw sinks to the bottom of the basin. Crossover piping and recycle pumps and plumbing have been clogged with sunken straw, potentially compromising basin capacity and requiring additional manpower to periodically unclog problem appurtenances. Sinking straw also increases organic loading in the basin, potentially compromising design storage capacity.